Transfer apparatus and method

Abstract

A transfer apparatus for moving a transfer stage. Two pairs of links are joined by a first pair of shafts. Each pair of links includes two arms joined together by a corresponding, respective shaft of the first pair of shafts. A second pair of shafts are driven by a driving unit. Each shaft of the second pair of shafts corresponds to a respective pair of links of the two pair of links and is attached to a first end of the corresponding pair of links. A third pair of shafts supports the transfer stage, each shaft of the third pair of shafts corresponding to a respective pair of links of the two pair of links and being attached to a second end of the corresponding pair of links. The second pair of shafts is inclined with respect to a perpendicular direction to the transfer direction of the transfer stage, to form an angle between the shafts of the second pair of shafts. One shaft of the first pair of shafts, one shaft of the third pair of shafts and one shaft of the second pair of shafts are parallel to each other. The other shaft of the first pair of shafts, the other shaft of the third pair of shafts and the other shaft of the second pair of shafts are parallel to each other. A magnetic unit exerts a force on the transfer stage to start a movement of the transfer stage.

What is claimed is: 
     
       1. A transfer apparatus for moving a transfer stage in a transfer direction, comprising: a first pair of shafts;   two pairs of links, each pair of links comprising two arms joined together by a corresponding respective shaft of the first pair of shafts and having a first end and a second end;   a driving unit;   a second pair of shafts which are driven by the driving unit, each shaft of the second pair of shafts corresponding to a respective pair of links of the two pair of links and being attached to the first end of the corresponding pair of links;   a third pair of shafts, each shaft of the third pair of shafts corresponding to a respective pair of links of the two pair of links and being attached to the second end of the corresponding pair of links; and   a transfer stage supported by the third pair of shafts, wherein: the second pair of shafts is inclined with respect to a direction which is perpendicular to the transfer direction, to form an angle between the respective shafts of the second pair of shafts,   one shaft of the first pair of shafts, one shaft of the third pair of shafts and one shaft of the second pair of shafts are parallel to each other, and   the other shaft of the first pair of shafts, the other shaft of the third pair of shafts and the other shaft of the second pair of shafts are parallel to each other.     
     
     
       2. The transfer apparatus as claimed in claim 1, wherein, for each pair of links, the distance between the corresponding shaft of the second pair of shafts and the corresponding shaft of the first pair of shafts is equal to or less than the distance between the corresponding shaft of the first pair of shafts and the corresponding shaft of the third pair of shafts. 
     
     
       3. A transfer apparatus for moving a transfer stage in a transfer direction, comprising: an intermediate link structure which is stretchable and contractible and comprises a plurality of pairs of links, each pair of links having a pair of arms joined together by a corresponding, respective intermediate rotary shaft, the intermediate link structure having a first end and a second end;   a first pair of arms rotatably coupled to the first end of the intermediate link structure;   a second pair of arms rotatably coupled to the second end of the intermediate link structure;   a driving unit;   a first pair of shafts driven by the driving unit and attached to the first pair of arms;   a second pair of shafts attached to the second pair of arms; and   a transfer stage supported by the second pair of shafts, wherein:   the first pair of shafts is inclined with respect to a direction perpendicular to the transfer direction, to form an angle between the respective shafts of the first pair of shafts, and   one shaft of the second pair of shafts is parallel to one shaft of the first pair of shafts and the other shaft of the second pair of shafts is parallel to the other shaft of the first pair of shafts.   
     
     
       4. A transfer apparatus for moving a transfer stage in a transfer direction, comprising: a first pair of shafts;   two pairs of links, each pair of links comprising two arms joined together by a corresponding, respective shaft of the first pair of shafts and having a first end and a second end;   a driving unit;   a second pair of shafts which are driven by the driving unit, each shaft of the second pair of shafts corresponding to a respective pair of links of the two pair of links and being attached to the first end of the corresponding pair of links;   a third pair of shafts, each shaft of the third pair of shafts corresponding to a respective pair of links of the two pair of links and being attached to the second end of the corresponding pair of links;   a transfer stage supported by the third pair of shafts; and   magnetic means for magnetically exerting a force on the transfer stage, to slightly move the transfer stage in the transfer direction.   
     
     
       5. The transfer apparatus as claimed in claim 4, wherein the magnetic means comprises: a coil attached to the driving unit; and   a permanent magnet attached to the transfer stage so that the permanent magnet is adjacent to the coil when the two pairs of links are completely contracted.   
     
     
       6. The transfer apparatus as claimed in claim 4, wherein the magnetic means comprises: a coil attached to the driving unit; and a secondary conductor attached to the transfer stage so that the secondary conductor is adjacent to the coil when the two pairs of links are completely contracted.   
     
     
       7. The transfer apparatus as claimed in claim 4, wherein the magnetic means comprises: a permanent magnet attached to the driving unit; and   a coil attached to the transfer stage so that the coil is adjacent to the permanent magnet when the two pairs of links are completely contracted.   
     
     
       8. The transfer apparatus as claimed in claim 4, wherein the magnetic means comprises: a secondary conductor attached to the driving unit; and   a coil attached to the transfer stage so that the coil is adjacent to the secondary conductor when the two pairs of links are completely contracted.   
     
     
       9. A transfer apparatus for moving a transfer stage in a transfer direction, comprising: an intermediate link structure which is stretchable and contractible and comprises a plurality of pairs of links, each pair of links having a pair of arms joined together by a corresponding, respective intermediate rotary shaft, the intermediate link structure having a first end and a second end;   a first pair of arms rotatably coupled to the first end of the intermediate link structure;   a second pair of arms rotatably coupled to the second end of the intermediate link structure;   a driving unit;   a first pair of shafts driven by the driving unit and attached to the first pair of arms;   a second pair of shafts attached to the second pair of arms;   a transfer stage supported by the second pair of shafts; and   magnetic means for magnetically exerting a force on the transfer stage, to slightly move the transfer stage in the transfer direction.   
     
     
       10. A transfer apparatus for moving a transfer stage in a transfer direction, comprising: a first pair of shafts;   two pairs of links, each pair of links comprising two arms joined together by a corresponding, respective shaft of the first pair of shafts;   a driving unit;   a second pair of shafts which are driven by the driving unit, each shaft of the second pair of shafts corresponding to a respective pair of links of the two pair of links and being attached to the first end of the corresponding pair of links;   a third pair of shafts, each shaft of the third pair of shafts corresponding to a respective pair of links of the two pair of links and being attached to the second end of the corresponding pair of links;   a transfer stage supported by the third pair of shafts; and   magnetic means for magnetically exerting a force on the transfer stage, to slightly move the transfer stage in the transfer direction, wherein: the second pair of shafts is inclined with respect to a direction which is perpendicular to the transfer direction, to form an angle between the respective shafts of the second pair of shafts,   one shaft of the first pair of shafts, one shaft of the third pair of shafts and one shaft of the second pair of shafts are parallel to each other, and   the other shaft of the first pair of shafts, the other shaft of the third pair of shafts and the other shaft of the second pair of shafts are parallel to each other.     
     
     
       11. A method for moving a transfer stage of a transfer apparatus in a transfer direction, the transfer apparatus comprising a first pair of shafts, two pairs of links, each pair of links comprising two arms joined together by a corresponding, respective shaft of the first pair of shafts and having a first end and a second end, a driving unit, a second pair of shafts which are driven by the driving unit, each shaft of the second pair of shafts corresponding to a respective pair of links of the two pair of links and being attached to the first end of the corresponding pair of links, a third pair of shafts, each shaft of the third pair of shafts corresponding to a respective pair of links of the two pair of links and being attached to the second end of the corresponding pair of links, and a transfer stage supported by the third pair of shafts, the method comprising: magnetically exerting a force on the transfer stage, to slightly move the transfer stage in the transfer direction; and   rotating the second pair of shafts to move the two pairs of links.